Water heater and method of mounting a heating element in a water heater

ABSTRACT

A water heater and a method of installing a heating element in a fluid heating apparatus. The water heater rests in relation to the floor and includes a water tank having a wall. A mounting device is coupled to the wall of the water tank. The water heater also includes a heating element coupled to the mounting device, the heating element having a greatest cross-sectional area. The heating element cooperates with the mounting device such that coupling the heating element to the mounting device ensures the greatest cross-sectional area of the heating element is level with respect to the floor.

FIELD OF THE INVENTION

The invention relates generally to a method and apparatus for mountingheating elements in a water heater. More specifically, the inventionrelates to a method and apparatus for assuring a particular orientationof the heating element within the water heater.

BACKGROUND

A storage-type water heater typically comprises a permanently enclosedwater tank, a cylindrical shell coaxial with and radially spaced apartfrom the water tank to form an annular space between the outer wall ofthe water tank and the inner wall of the shell, and insulating materialin at least a portion of the annular space for providing thermalinsulation to the water tank. The water tank has various appurtenancessuch as inlet, outlet, and drain fittings. Additionally, the waterheater is provided with a water heating and temperature control system.In electric water heaters, the water heating and temperature controlsystem includes one or more electrical resistance heating elements.

SUMMARY

The water tank has tank characteristics that are used in determining thethermal profile of the tank. The tank characteristics may include, butare not limited to, tank diameter, tank height, tank storage capacity,etc. The tank characteristics determine heating convection current flowpatterns within the tank that create different temperature water stratalayers in the tank. Another characteristic that determines heatingconvection current flow patterns is the placement and position of theheating element in the tank. Some heating element positions improve thecurrent flow patterns in the tank. It is thus desirable to mount theheating element within the tank in a position that maximizes the currentflow patterns within the tank to increase the efficiency of the waterheater.

Accordingly, and in one embodiment, the invention provides a waterheater that rests in relation to the floor. The water heater includes awater tank having a wall, a mounting device coupled to the wall of thewater tank, and a heating element coupled to the mounting device. Theheating element includes a greatest cross-sectional area and cooperateswith the mounting device such that coupling the heating element to themounting device ensures the greatest cross-sectional area of the heatingelement is level with respect to the floor.

In some embodiments, the mounting device is threaded and the heatingelement includes mating threads. In other embodiments, at least one ofthe heating element and the wall of the tank includes an identificationmark such that aligning the identification mark in a predeterminedposition results in the greatest cross-sectional area of the heatingelement being level with respect to the floor. In other embodiments, themounting device includes a mounting flange and the heating elementincludes a heating element flange that cooperates with the mountingflange. In yet other embodiments, the water heater includes a resilientgasket placed between the cooperating mounting flange and heatingelement flange, and a compression element is coupled to the matingflanges, compressing the gasket therebetween to form a water-tight sealbetween the mounting flange and heating element flange.

The invention also provides for a method of installing a heating elementin a fluid heating apparatus. The method includes providing a fluid tankwithin the fluid heating apparatus, the fluid tank having a wall,coupling a mounting device to a wall of the fluid tank, and coupling aheating element to the mounting device to ensure that the greatestcross-sectional area of the heating element is level with respect to thefloor.

Other features and advantages of the invention will become apparent tothose skilled in the art upon review of the following detaileddescription, claims, and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view of a water heater embodying aspects of theinvention.

FIG. 2 is a top view of a heating element for use in the water heater ofFIG. 1.

FIG. 3 is a side view of the heating element of FIG. 2.

FIG. 4 is a top exploded sectional view of the water heater of FIG. 1illustrating the heating element coupled to a mounting device.

FIG. 5A is an end view of a single-start threaded connector.

FIG. 5B is a side view of the threaded connector of FIG. 5A.

FIG. 6A is an end view of a two-start threaded connector.

FIG. 6B is a side view of the threaded connector of FIG. 6A.

FIG. 7A is an end view of a three-start threaded connector.

FIG. 7B is a side view of the threaded connector of FIG. 7A.

FIG. 8A is an end view of a four-start threaded connector.

FIG. 8B is a side view of the threaded connector of FIG. 8A.

FIG. 9 is an end view of the heating element of FIG. 2, illustrating anidentification mark.

FIG. 10 is a partial exploded perspective view of another constructionof a water heater embodying aspects of the invention.

FIG. 11 is an enlarged view taken along line 11-11 of FIG. 10.

FIG. 12 is an enlarged view of an alternate mounting device capable ofbeing used with the water heater of FIG. 10.

DETAILED DESCRIPTION

Before any embodiments of the invention are explained in detail, it isto be understood that the invention is not limited in its application tothe details of construction and the arrangement of components set forthin the following description or illustrated in the following drawings.The invention is capable of other embodiments and of being practiced orof being carried out in various ways. Also, it is to be understood thatthe phraseology and terminology used herein is for the purpose ofdescription and should not be regarded as limiting. The use of“including,” “comprising,” or “having” and variations thereof herein ismeant to encompass the items listed thereafter and equivalents thereofas well as additional items. The terms “connected,” “coupled,” and“mounted” and variations thereof herein are used broadly and, unlessotherwise stated, encompass both direct and indirect connections,couplings, and mountings. In addition, the terms connected and coupledand variations thereof herein are not restricted to physical andmechanical connections or couplings.

FIG. 1 shows a sectional view of an electric water heater 10 comprisinga vessel. With reference to FIG. 1, the vessel is defined as one of anenclosed water tank 11 or a shell 12 surrounding the water tank 11. Foaminsulation 13 fills the annular space between the water tank 11 and theshell 12. A water inlet line or dip tube 14 and a water outlet line 15enter the top of the water tank 11. The water inlet line 14 has an inletopening 22 for adding cold water near the bottom of the water tank 11.The water outlet line 15 has an outlet opening 24 for withdrawing hotwater from near the top of the water tank 11. The water heater 10 isconfigured to rest on a support surface, such as the floor 25. In theillustrated construction, the water heater 10 includes an axis A that issubstantially perpendicular to the floor 25.

A heating element 16 extends through the wall of the water tank 11. Inthe illustrated embodiment, the heating element 16 is an electricresistance heating element. However, other types of heating elements canbe used. The mounting of the heating element 16 to the wall of the watertank 11 will be described in more detail below.

The temperature control circuitry controls the heating of the water. Thetemperature control circuitry includes a controller (in control box 17),a temperature sensor assembly 18, and the heating element 16. In oneconstruction, the temperature control circuitry includes a burst controlcircuit for providing power to the resistance heating element in bursts.The details of a burst control circuit are described in U.S. Pat. No.6,633,726, entitled METHOD OF CONTROLLING THE TEMPERATURE OF WATER IN AWATER HEATER, issued Oct. 14, 2003, the entire disclosure of which isincorporated herein by reference. However, the temperature controlcircuitry can use other circuitries and other methodologies for heatingthe water.

In some constructions, the temperature control circuitry in control box17 includes a programmable real time clock. Peak or off-peak energydemand periods or vacation operation cycles are programmed into thecontrol cycle for the heating element. Additionally, a pressure sensor,temperature sensor, mineral deposit sensor and/or sensor for detectingthe presence of water could be added. In one method of operation of thewater heater 10, the control circuit is programmed to disconnect powerfrom the heating element when predetermined conditions or limits aredetected.

Referring again to FIG. 1, the temperature sensor assembly 18 is coupledto the outer wall of the water tank 11 to sense the temperature of waterin the tank 11. The temperature sensor assembly can include one or morethermistors for sensing the temperature of the water in the tank 11.When multiple thermistors are used, the thermistors are placedthroughout the tank to measure water temperature at a plurality oflocations, and the output of the thermistors can be averaged. However,the temperature sensor assembly can use other types of temperaturesensors and can be simply a single sensor.

The temperature sensor assembly 18 is connected to the controller, forexample, by an electrical wire 19. The controller is a known controlsystem in the art that is in communication with the heating element 16and the temperature sensor assembly 18 and generates a signalcontrolling the heating element in response to the temperature sensed bythe sensor assembly 18. The controller can include an integratedcircuit, a programmable device, discrete circuit elements, a processorand memory that are software driven, and similar components. Thecontroller may include a switching element (not shown), such as athyristor or a triac, to selectively power the heating element.

Electric alternating current (A.C.) power is supplied to the waterheater 10 through line 20. A customizable operator interface (not shown)can be mounted on the outside of the water heater to permitcommunication with the controller and provides security protected accessfor control of the heating element. The operator interface may beoperable to provide direct or remote control of the heating element.

FIG. 2 illustrates the heating element 16 in more detail. As illustratedin FIG. 2, the heating element 16 of the illustrated embodiment issubstantially U-shaped when viewed from the top. However, it isunderstood that any shape of heating element, such as a round orcircular loop, a flat helix design, a serpentine pattern, or othershapes, can be used with the water heater 10. The heating element 16includes a greatest cross-sectional area 26, best shown in FIG. 2.

With reference to FIGS. 2-4, the heating element 16 also includes aheating element flange 28 that mates with a mounting flange 30 of amounting device 32 coupled to a wall of the water tank 11. As usedherein, the term “flange” means not only a traditional mechanicalflange, but any mount on the heating element that mates with a mount onthe mounting device to assist in coupling the heating element 16 to thetank 11.

The heating element flange 28 includes threads 34. The heating element16 further includes an electrical connector portion 36 that includeselectrical contacts 40 (also shown in FIG. 9) that are in communicationwith the controller for controlling the heating of the water in the tank11.

A gasket is also coupled to the heating element 16. In the illustratedembodiment, the gasket is a compressible O-ring 44 that can be made ofany temperature-tolerant resilient material, such as neoprene, silicone,rubber, etc. It is understood that the gasket can be of anyconfiguration and/or material that is capable of providing a resilientseal between the heating element 16 and the mounting device 32. Thefunction of the O-ring 44 will be discussed in more detail below.

As mentioned above, a mounting device 32 is coupled to a wall of thewater tank 11. The mounting device 32 is generally welded to a wall ofthe tank 11 and is configured to receive the heating element 16. Asshown in FIG. 4, the mounting device 32 includes the mounting flange 30having threads 48 that mate with the threads 34 of the heating element16. Threading the heating element 16 into the mounting device 32 alsofunctions to compress the O-ring 44 therebetween to form a water-tightseal between the mounting device 32 and the heating element 16.

In the illustrated construction, the threads 48 of the mounting flange30 and the mating threads 34 of the heating element 16 are multi-lead ormulti-start threads. FIGS. 5A and 5B illustrate an end view and a sideview of a single-start threaded connector 50. When looking at asingle-start threaded connector 50 in an end view, the threads form anoffset circular shape. In contrast, with reference to FIGS. 6A, 7A, and8A, a two-start threaded connector 52 will have a somewhat oval orfootball shape in an end view, a three-start threaded connector 54 willhave a tri-oval shape, and a four-start threaded connector 56 will havea four-cornered shape in the end view.

The more starts or leads that the threaded connector has, the faster themating threads will travel along the threaded connector. This occursbecause using multiple starts increases the number of starting points athread will engage in a mating part with fewer degrees of rotation,increasing the thread contact area (when compared to a thread with thesame lead but using a single start). This can be illustrated in thefollowing way: if one places a pencil in a thread groove 58 of asingle-start threaded connector 50 and rotate the threaded connector360° (i.e., one full revolution), the mark 60 left by the pencil in thegroove will end in the adjacent thread groove 58 (see FIG. 5B). Incontrast, placing a pencil in a groove 58 of a two-start threadedconnector 52 and rotating the threaded connector 52 one full revolutionwill result in one groove 58 existing between the ends of the mark 60(see FIG. 6B). Two grooves 58 will exist between the ends of the mark 60made on a three-start threaded connector 54 (see FIG. 7B), and so on.Utilizing multi-start threads in the illustrated construction functionsto speed the installation of the heating element 16 into the mountingdevice 32, as well as making adjustment of the heating element 16 duringthe threading process more precise. However, it is understood thatsingle-start threads could be used as the mating threads 34.

In some constructions, the heating element 16 also includes anidentification mark that assists a user in coupling the heating element16 to the mounting device 32 when a particular heating elementorientation within the tank 11 is desired. As illustrated in FIG. 9, theidentification mark is an arrow 64 that indicates a particular heatingelement orientation. The arrow 64 is pointed upward with respect to thefloor 25, and may include the word “Up” inside the arrow to indicate toa person installing the heating element 16 in the tank 11 what the finalorientation of the heating element 16 should be. It is understood thatin other constructions utilizing an identification mark, other types ofmarks could be used, so long as the identification mark assists in theinstallation of the heating element to obtain the desired finalorientation of the heating element 16 in the tank 11. It is alsounderstood that in some constructions, an identification mark may alsobe placed on the outside of the wall of the tank 11 instead of, or inconjunction with, the identification mark on the heating element for thesame purpose. For example, the identification mark on the heatingelement could be a straight line mark or the bottom half of a shape(such as a semi-circle) that needs to be matched with a mating mark(e.g., a second straight line or semi-circle) found on the water tank 11to obtain the desired final orientation of the heating element 16.

In the illustrated constructions, the desired final orientation of theheating element 16 within the tank 11 is such that the greatestcross-sectional area 26 of the heating element 16 is level with respectto the floor 25, as shown in FIGS. 1 and 4. As used herein, the term“level” means that the heating element 16 is at least substantiallyparallel to the ground in an upright water heater such as illustrated inFIG. 1 and that slight variations from absolute level are possible dueto mechanical tolerances and slight variations in the floor and stillfall within the definition of “level.” Put another way, the greatestcross-section 26 of the heating element 16 is preferably substantiallyperpendicular to the axis A of the water heater 10.

The level orientation results in better thermal transfer from theheating element 16 to the water in the tank 11 because the greatestcross-section 26 of the heating element 16 is exposed to convectioncurrents within the water, thereby improving the efficiency of theconvection currents. This results in an improved recovery time for thewater heater 10, and increases the overall efficiency of operation ofthe water heater 10.

FIGS. 10 and 11 illustrate an alternate construction of a mountingdevice 70. Like reference numerals will be given to like parts asappropriate.

As shown in FIGS. 10 and 11, the heating element 16 includes a heatingelement flange 74 that mates with a mounting flange 78 of the mountingdevice 70. Each of the heating element flange 74 and mounting flange 78have a plurality of apertures 82, 84 that align with each other when theheating element flange 74 is coupled to the mounting flange. Theapertures are configured to receive a fastener 86 therethrough. It isunderstood that the fastener could be a screw, a bolt, a weldment, arod, or any other appropriate mechanical fastening system. In theillustrated construction, five apertures 82, 84 are spaced at pointsaround the flanges to receive up to five fasteners 86 therethrough tocouple the heating element 16 to the tank 11. However, it is understoodthat any number of apertures and fasteners can be used to couple theheating element 16 to the tank 11.

A circular resilient gasket 90 is also provided to fit between theheating element flange 74 and mounting flange 78. The gasket 90 includesapertures 94 that align with the apertures 82, 84 in the flanges. Theheating element 16 is coupled to the mounting device by aligning theapertures 82, 84 in the heating element flange 74 and mounting flange 78with the apertures 94 in the gasket 90. Once the apertures are aligned,the fasteners 86 are placed through the apertures to couple the heatingelement 16 to the tank 11. The fasteners 86 are tightened to compressthe gasket 90 between the flanges, forming a water-tight seal betweenthe heating element 16 and the tank. In this way, the fasteners 86function as a compression element, compressing the gasket 90 to form theseal.

The pattern of apertures 82, 84, 94 in the heating element flange 74,mounting flange 78, and gasket 90, respectively, function as anidentification mark to assist in the installation of the heating element16 to obtain the desired level orientation of the heating element 16discussed in detail above. If the pattern of apertures 82 on the heatingelement flange 74 is matched to the pattern of apertures 84 on themounting flange 74 when the heating element is installed, the heatingelement 16 of FIGS. 10 and 11 will be mounted within the tank 11 suchthat the greatest cross-sectional area 26 is level with respect to thefloor 25. By matching the pattern of apertures 82 on the heating elementflange 74 to the pattern of apertures 84 on the mounting flange 78 andthe gasket 90, the operator ensures that the heating element 16 will bemounted with the desired orientation within the tank 11.

FIG. 12 illustrates yet another alternate construction of a mountingdevice 100. Like reference numerals will be given to like parts whereappropriate.

As illustrated in FIG. 12, the heating element 16 includes anon-threaded heating element flange 104 that mates with a non-threadedmounting flange 108 of the mounting device 100. The heating elementflange 104 and the mounting flange 108 are generally cylindrical inshape. The heating element flange 104 is slightly smaller in diameterthan the mounting flange 108 such that the heating element flange 104fits within the mounting flange 108 to couple the heating element 16 tothe tank 11. It is understood that in other embodiments, the mountingflange might have a smaller diameter such that the mounting flange fitswithin the heating element flange.

The mounting flange 108 and the heating element flange 104 are designedsuch that the flanges will only cooperate with each other in apredetermined position to ensure that the heating element 16 is coupledto the tank 11 in the desired orientation (i.e., the heating element 16is level with respect to the floor 25). In the illustrated construction,the mounting flange 108 includes a protrusion 112 and the heatingelement flange includes a channel 116 that receives the protrusion 112when the heating element 16 is coupled to the mounting device 100.Aligning the protrusion 112 and the channel 116 to couple the heatingelement 16 to the tank 11 ensures the desired final orientation of theheating element. It is understood that in other constructions, theprotrusion could be located on the heating element flange and thechannel located on the mounting flange. It is also understood that othertypes of mating mechanisms could be used on the heating element flangeand mounting flange to ensure the desired orientation. For example, theprotrusion can be a bump that cooperates with a channel, a notch, orother aperture, the protrusion could be a rod, nail, screw, weldment, orbolt that is received by a notch, channel, or other aperture, or themating mechanism could be a ball and spring detent mechanism as is wellknown in the art. In other constructions, multiple protrusions ofvarious geometrical configurations could be used that fit within anaperture of mating geometric configuration. These and other matingmechanisms that ensure that the heating element is mounted within thetank in a desired configuration are possible and would fall within thescope of the present invention.

A cylindrical gasket 120 is coupled to the heating element flange 104such that when the heating element 16 is coupled to the mounting device100, the gasket 120 fits between the heating element flange 104 and themounting flange 108. The gasket 120 includes a channel 124 that alignswith the channel 116 on the heating element flange 104 such that whencoupled between the flanges, the channel 124 also receives theprotrusion 112. A compression element, such as a clamp 128, is coupledto the outside of the mounting flange 108. The clamp 128 of theillustrated construction is a hose clamp, but it is understood that inother constructions, other types of clamps, including other mechanicalclamps, and other types of compression elements can be used. When theheating element flange 104 and gasket 120 are coupled within themounting flange 108, the clamp 128 is tightened by turning screw 132 tocompress the gasket 120 between the flanges 104, 108, providing awater-tight seal between the heating element 16 and the tank 11.

The mounting devices discussed above can also be utilized to perform amethod of installing a heating element in a water heater. The mountingdevice is coupled to a wall of the water tank 11, such as by welding,gluing, soldering, conventional fastening, or other known mechanicalcoupling methods. The heating element flange is then mated with themounting flange, coupling the heating element 16 to the mounting deviceto ensure that the greatest cross-sectional area 26 is level withrespect to the floor 25. Coupling the heating element flange to themounting flange compresses the flanges to form a water-tight sealbetween them.

In the construction illustrated in FIGS. 1 and 4, coupling the flangesincludes threading the heating element flange 28 into the mountingflange 30. Threading the flanges together also function to compress theO-ring 44 between the flanges, providing a water-tight seal between theflanges. To assist a person installing the heating element 16 inobtaining the desired level orientation of the heating element 16 withinthe tank 11, the method can also include aligning the identificationmark (the arrow 64 in the illustrated embodiment) in the predeterminedposition to ensure the level orientation. It is understood that while inthe illustrated construction the heating element 16 is manuallyinstalled, in other constructions the heating element can beautomatically installed by a robot or other machinery. In suchconstructions, the identification mark would be aligned by the machineto ensure the desired orientation.

In the construction of FIGS. 10 and 11, coupling the flanges includesaligning the apertures 82, 84, and 94 of the heating element flange 74,the mounting flange 78, and the gasket 90 such that the gasket 90 fitsbetween the heating element flange 74 and mounting flange 78. Thefasteners 86 are then inserted through the apertures and are tightenedto couple the heating element 16 to the tank 11. The tightening of thefasteners 86 compresses the gasket 90 between the flanges, providing awater-tight seal between the heating element 16 and the tank 11.

In the construction of FIG. 12, coupling the flanges includes placingthe clamp 128 around the outside of the mounting flange 108, and placingthe gasket 120 on the heating element flange 104 such that the channels116, 124 are aligned. The channel 116 of the heating element flange 104is then mated with the protrusion 112 of the mounting flange 108 and theheating element flange 104 is inserted into the mounting flange 108 withthe gasket 120 therebetween. The clamp 128 is tightened down over themated flanges, compressing the gasket 120 therebetween to form awater-tight seal between the heating element 16 and the tank 11.

The above-described methods and apparatus have been illustrated anddescribed for use in a storage-type, electric water heater. However, itis understood that in other constructions, the methods and apparatusillustrated in FIGS. 1-12 could also be used in other types of fluidheating apparatus and still fall within the scope of the presentinvention. For example, the mounting device and method of mounting couldbe used in a commercial or industrial coffee maker, or any other fluidheating apparatus having a tank that holds fluid to be heated, and wherethe heating element is coupled to the tank such that the heating elementis exposed to the fluid within the tank. Utilizing the mounting deviceand method of mounting in any similar fluid heating apparatus wouldassist in the installation of the heating element in the tank to ensurethe desired level orientation of the heating element within the fluidtank.

Various other features and advantages of the invention are set forth inthe following claims.

1. A water heater that rests in relation to the floor, the water heatercomprising: a water tank having a wall; a mounting device coupled to thewall of the water tank; and a heating element coupled to the mountingdevice, the heating element comprising a greatest cross-sectional areaand cooperating with the mounting device such that coupling the heatingelement to the mounting device ensures the greatest cross-sectional areaof the heating element is level with respect to the floor.
 2. The waterheater of claim 1, wherein the mounting device is threaded and theheating element includes mating threads.
 3. The water heater of claim 2,wherein the threads on the mounting device and heating element comprisemulti-start threads.
 4. The water heater of claim 1, wherein at leastone of the heating element and the wall of the tank includes anidentification mark such that aligning the identification mark in apredetermined position results in the greatest cross-sectional area ofthe heating element being level with respect to the floor.
 5. The waterheater of claim 4, wherein the identification mark is located on theheating element.
 6. The water heater of claim 4, wherein theidentification mark comprises an arrow.
 7. The water heater of claim 1,wherein the mounting device includes a mounting flange, and wherein theheating element includes a heating element flange that cooperates withthe mounting flange.
 8. The water heater of claim 7, further comprisinga compression element placed over the cooperating mounting flange andheating element flange, the compression element compressing the flangesto form a water-tight seal between the mounting flange and heatingelement flange.
 9. The water heater of claim 8, wherein the compressionelement comprises a clamp.
 10. The water heater of claim 7, furthercomprising a resilient gasket placed between the cooperating mountingflange and heating element flange, wherein a compression element iscoupled to the mating flanges, compressing the gasket therebetween toform a water-tight seal between the mounting flange and heating elementflange.
 11. The water heater of claim 10, wherein the compressionelement comprises a fastener.
 12. A method of installing a heatingelement in a fluid heating apparatus, the fluid heating apparatusconfigured to rest in relation to the floor, the method comprising:providing a fluid tank within the fluid heating apparatus, the fluidtank having a wall; coupling a mounting device to the wall of the fluidtank, the mounting device configured to receive a heating element; andcoupling the heating element to the mounting device to ensure thegreatest cross-sectional area of the heating element is level withrespect to the floor.
 13. The method of claim 12, wherein coupling theheating element to the mounting device includes threading the heatingelement into the mounting device.
 14. The method of claim 13, whereinthreading the heating element into the mounting device includesutilizing multi-lead threads.
 15. The method of claim 12, whereincoupling the heating element to the mounting device includes coupling aheating element flange to a mounting flange.
 16. The method of claim 15,wherein the heating element flange and the mounting flange areconfigured such that the flanges will only cooperate in a predeterminedposition to ensure that the greatest cross-sectional area of the heatingelement is level with respect to the floor.
 17. The method of claim 15,further comprising compressing the heating element flange and mountingflange with a compression element to form a water-tight seal between theheating element flange and the mounting flange.
 18. The method of claim12, further comprising providing an identification mark on at least oneof the heating element and the wall of the tank.
 19. The method of claim18, wherein coupling the heating element to the mounting device includesaligning the identification mark in a predetermined position such thatthe greatest cross-sectional area of the heating element is level withrespect to the floor.
 20. A method of mounting a heating element to awall of a water tank in a water heater, the water heater configured torest in relation to the floor, the method comprising: coupling amounting device to a wall of the water tank, the mounting deviceconfigured to receive a heating element; aligning an identification markon the heating element in a predetermined position; and coupling theheating element to the mounting device such that the greatestcross-sectional area of the heating element is level with respect to thefloor.
 21. The method of claim 20, wherein coupling the heating elementto the mounting device includes threading the heating element into themounting device.
 22. The method of claim 20, wherein coupling theheating element to the mounting device includes coupling a heatingelement flange to a mounting flange.
 23. The method of claim 22, furthercomprising compressing the heating element flange and mounting flangewith a compression element to form a water-tight seal between theheating element flange and the mounting flange.
 24. A water heaterconfigured to rest on the floor and having an axis substantiallyperpendicular to the floor, the water heater comprising: a water tankhaving a wall; a mounting device coupled to the wall of the water tank;a heating element coupled to the mounting device, the heating elementhaving a greatest cross-sectional area; and a means for ensuringplacement of the heating element within the water tank such that thegreatest cross-sectional area of the heating element is substantiallyperpendicular to the axis.
 25. The water heater of claim 24, wherein themeans for ensuring placement comprises cooperating multi-start threadson the mounting device and the heating element and an identificationmark on at least one of the wall of the water tank and the heatingelement.
 26. The water heater of claim 24, wherein the means forensuring placement comprises an identification mark on at least one ofthe wall of the water tank and the heating element such that aligningthe identification mark in a predetermined position results in thegreatest cross-sectional area of the heating element being perpendicularto the axis.
 27. The water heater of claim 26, wherein theidentification mark comprises an arrow.
 28. The water heater of claim24, wherein the means for ensuring placement comprises a mounting flangeof the mounting device configured to receive a heating element flange ofthe heating element in only a predetermined position.
 29. The waterheater of claim 28, wherein the mounting flange and heating elementflange are non-threaded, and wherein one of the mounting flange andheating element flange fits over the other of the mounting flange andheating element flange.
 30. The water heater of claim 29, wherein one ofthe mounting flange and heating element flange includes a protrusion,and wherein the other of the mounting flange and heating element flangeincludes a recess configured to accept the protrusion such that theheating element is mounted to the tank wall in a position that resultsin the greatest cross-sectional area being substantially perpendicularto the axis.
 31. The water heater of claim 29, further comprising acompression element placed over the mounting flange and heating elementflange.
 32. The water heater of claim 31, wherein the compressionelement comprises a clamp.
 33. The water heater of claim 28, furthercomprising a resilient gasket placed between the cooperating mountingflange and heating element flange, wherein a compression element iscoupled to the mating flanges, compressing the gasket therebetween toform a water-tight seal between the mounting flange and heating elementflange.
 34. The water heater of claim 24, further comprising a resilientgasket between the mounting device and heating element such thatcoupling the heating element to the mounting device compresses thegasket between the heating element and the mounting device to ensure awater-tight seal.